Containing Marburg in Uganda

Amesh A. Adalja, MD, FACP, October 10, 2014

While the Ebola outbreak in West Africa continues to evolve, an outbreak of the closely related filovirus, Marburg virus, has appeared in the East African country of Uganda.1Understanding how Uganda—a nation that has faced Ebola in the past—responds to this latest appearance of Marburg will be an important illustration of outbreak management principles that are equally applicable to Ebola.

Case Fatality Rates Can Reach 80%

Marburg was the first filovirus to be identified when, in 1967, a shipment of monkeys from Africa sparked an outbreak of an unknown and fatal disease in Marburg, Germany. Spread through blood and bodily fluids, Marburg’s case fatality rates can reach levels rivaling those of Ebola. Like Ebola, signs and symptoms of Marburg include fever, rash, myalgia, nausea, vomiting, and diarrhea. The animal reservoir for Marburg has been shown to be the African fruit bat, a fact that provides the basis for assuming Ebola’s reservoir also is a species of bat. There is no licensed vaccine or antiviral available for Marburg.2

Appearance in America

Prior to the current Ebola outbreak, Marburg was the only symptomatic human filovirus infection that had been diagnosed in the US. In 2008, a traveler who had returned from Uganda and then developed a febrile illness in Colorado was treated with supportive care and recovered. Retrospectively, the patient was discovered to have been infected with Marburg. Importantly, no secondary transmission occurred from this case despite the fact that the patient’s caregivers had no awareness of the etiology of the patient’s illness.3

Current Situation

The current appearance of Marburg in Uganda began when a healthcare worker succumbed to a febrile illness that was later confirmed to be Marburg. The patient is said to have had approximately 80 contacts, including 60 healthcare workers, all of whom have been isolated. Symptoms of the disease have developed in 8 of those contacts. The fact that this case occurred in a healthcare worker suggests that it is likely that the healthcare worker had come in contact with an undiagnosed index case. This might imply that an even larger unrecognized outbreak may be ongoing.1,4

Implications for Ebola

Two aspects of the Marburg case in Uganda illustrate important outbreak management steps that are wholly applicable to Ebola outbreaks:

Rapid diagnosis: Within days, health officials in Uganda determined the etiology of the illness, allowing public health measures to be rapidly initiated.

Contact tracing and identification: Rapid identification of contacts is essential to identifying cases as they develop.

As this Marburg outbreak continues in a nation with decades of experience with filovirus outbreaks, it may provide an important point of contrast for the concurrent Ebola outbreak in West Africa, as does the concurrent Ebola outbreak in the Democratic Republic of Congo.